Correct voltage

Let me apologize up front since this is not exactly on topic but it
is for a vacuum table on my CNC router, which will be activated by a
relay from my CAM system. :-|

I have a vacuum pump, which specifies on the label:

220 volt 1.9 amp
240 volt 2.2 amp

I have a transformer, which can give me 210, 230 or 250 volts. I want
the most torque since vacuum is more important to me than volume. It
seems from the label on the vacuum that allowable amperage increases
with voltage. This does not seem right to me since the allowable
wattage would increase with voltage.

Now the questions. Can I go to 250 on my transformer? Should I, if I
want the most torque? At what amperage do I fuse the circuit?